Here are two loads using Winchester powders to approximate the Super HCP load in Winchester Hulls. I have used the WSF powder before and don't care to load as high as 11,300 PSI on a regular basis, so I have not personally tested the Super HCP powder in the following load. I have tried it at lower pressures for 1200 fps and found it satisfactory. The WSF load is just a little bit "boomy". There are many other good powder choices for a 1250 fps load. Winchester did not appear to provide the loading details for their 1250 fps load like they had done previously for other target loads.
Lead Shot 12ga 1 1/8 oz. Super Hcp Win. 209 WAA12 20.9 gr 11,300 PSI 1255 fps
Lead Shot 12ga 1 1/8 oz. WSF Fed. 209A WAA12SL 24.0 gr 9,100 PSI 1255 fps